yes, it's quite normal.
Dicor is what's used on roof. it can be a diy job. many RV owners do it themselves. should be able to find videos on how to remove and re-caulk.
without pics of what you're talking about on the sides, can't say. there is a Dicor product for vertical applications, different than for the roof.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC